activity trackers

Suellen bought me one of those activity-tracking wristbands for my birthday. It keeps track of what I do — including how much time I spend sitting around, how often I’m up and about, how many steps I take, how long I sleep, (including light sleep versus deep sleep), and so on. It will even beep if I sit still too long. It’s telling me to get up, move around, and keep my blood from pooling.

It also calculates how many calories I’ve burned and consumed each day. The system has a good database of foods that I can pick from (or add to). I can, for instance, pick chicken sandwich from the database and learn that I’ve consumed 252 calories, 26 grams of carbs, 20 grams of protein, 466 milligrams of sodium, and 47 milligrams of cholesterol.

I always thought that I kept close tabs on my diet. But the activity tracker delivers much closer scrutiny. I’ve learned a lot about sodium and cholesterol, for instance. I’ve also learned that a glass of red wine has 130 calories while a glass of bourbon has only 50. That’s useful knowledge.

I’ve also re-learned an old lesson: if you observe something, it changes. Simply observing what I eat has changed what I eat. I can ask myself, “I’ve eaten how many calories today? Do I really need that third cheeseburger?”

I’m certainly not the first one to observe this effect. In social science, it’s known as the Hawthorne Effect and derives from experiments in the 1920s at the Hawthorne Works, a Western Electric factory near Chicago. It was the early days of industrial engineering and researchers wanted to know if lighting levels would affect productivity. The researchers measured productivity at an initial level of illumination. Then they improved the illumination and noted that productivity increased. They improved illumination again and productivity improved again. Each time the researchers improved illumination productivity improved.

So, we can conclude that better lighting yields better productivity, correct? Well, not so fast. At the end of the trials, the researchers returned the illumination to its initial level and … productivity improved yet again. The researchers weren’t measuring the effects of illumination at all. They were measuring the effects of observation. When observed, the workers changed their behavior. Perhaps they enjoyed the attention. Perhaps they were angling for a raise. But the mere fact that they were observed, changed their behavior.

In physics, the same (general) phenomenon is known as the Heisenberg Uncertainty Principle. In 1927, Werner Heisenberg stated the basic principle: you can know a subatomic particle’s position or you can know its momentum but you can’t know both. The more certain you are of one, the more uncertain you are of the other. Why can’t you know both? Because of the “… jolt-like disturbance triggered by the act of observation.” If you observe a subatomic particle, it changes its behavior. (Since Heisenberg’s time, the effect has been found in many physical systems and it’s generally known as the observer effect).

We can see similar effects in everyday life. If I don’t know that you’re taking my picture, I’ll behave one way. If I do know, I’ll behave another way (and show you my best side). If I don’t know that a policeman is around, I’ll behave one way. If I do know, I’ll behave another way (most likely).

It’s also a good management principle to keep in mind. A process that’s observed will change its behavior. The more closely you observe, the greater the change. If you want to change something, whether it’s your diet or factory productivity, just pay attention.